integration vs merger

integration and merger both are nouns.

Word	Noun	Adjective	Verb	Adverb
integration	Yes	No	No	No
merger	Yes	No	No	No

As nouns, merger is a hyponym of integration; that is, merger is a word with a more specific, narrower meaning than integration:

integration (noun)	merger (noun)
the action of incorporating a racial or religious group into a community	the combination of two or more commercial companies
the act of combining into an integral whole	an occurrence that involves the production of a union
an operation used in the calculus whereby the integral of a function is determined